Abstract 15208: Association Between Electrocardiographic St-t Wave Abnormalities and Stroke Risk in the Allhat Trial

Background: The presence of electrocardiographic (ECG) ST-T wave abnormalities has previously been shown to be associated with increased risk of coronary artery disease but their association with stroke incidence is unclear.Objective: We sought to investigate the relationship between ST-T wave abnormalities and stroke incidence in the ALLHAT trial. Methods: The Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) is a randomized double-blinded clinical trial (n=33,357) conducted from 1994 through 2002, examining whether treatment with a calcium channel blocker or an angiotensin-converting enzyme inhibitor lowers incidence of CHD or CVD events compared to treatment with a diuretic. Major ST depression or T wave inversion on any ECG in the past 2 years were included in the study. One of the secondary outcomes included in the study was incident stroke. Hazard ratios (relative risks [RRs]) and 95% confidence intervals (CIs) were obtained using Cox proportional hazards regression model. All statistical analyses were performed using STATA 12 (Stata Corp., College Station, TX, USA). Results: Study participants were predominantly middle-aged, male, white, with prevalence of ST-T wave abnormality being 10.35% (N=3,420). Presence of ST-T wave abnormalities were not associated with a higher risk of stroke [hazard ratio 0.47 (95% CI, 0.91-1.22)] in unadjusted analyses. This relationship was not significant even after adjustment for prevalent cardiovascular disease (CABG, ASCVD) [0.51(95% CI, 0.91- 1.22)], cardiovascular risk factors (age, sex, diabetes, systolic blood pressure, diastolic blood pressure, cholesterol, BMI) [0.15 (95% CI, 0.96-1.31)] as well as randomized treatment groups in ALLHAT [0.15 (95% CI, 0.96-1.31)]. Conclusion: Presence of major ST-T wave abnormality does not predict incident stroke in the the ALLHAT trial, more observations from contemporary studies need to be elucidated.